/* Rexx */                                                                      
/*-------------------------------------------------------------------*/         
/*                                                                   */         
/*                      Edit Macro : CENTER                          */         
/*                                                                   */         
/*  Description : Centers the lines on the line                      */         
/*                                                                   */         
/*  Created on : 18 Oct 1998                                         */         
/*  Created by : Kevin Ferguson                                      */         
/*             : Userid(MIT001)                                      */         
/*             : using ABBYDALE.ALLFREE.EMACS(CENTER)                */         
/*                                                                   */         
/*  Called by : Nothing                                              */         
/*                                                                   */         
/*  Calls : Nothing                                                  */         
/*                                                                   */         
/*  Change Activity :                                                */         
/*                                                                   */         
/*                ©Copyright of Abbydale Systems LLC.                */         
/*                                                                   */         
/*-------------------------------------------------------------------*/         
Address ISREDIT "MACRO (left,right) NOPROCESS"                                  
If left = "?" Then do                                                           
    'ISPEXEC DISPLAY PANEL(ASLCNTR1)'                                           
    Exit (1)                                                                    
    End                                                                         
If left ^= ""  & right = " " then do                                            
    ISREDIT '(L2,right) = BOUNDS'                                               
    End                                                                         
Address ISPEXEC "CONTROL ERRORS RETURN"                                         
Address ISREDIT "PROCESS RANGE C"                                               
Address ISREDIT "(RC) = RANGE_CMD"                                              
If rc = 4 Then Do                                                               
    zedsmsg = "NO RANGE SPECIFIED"                                              
    zedlmsg = "You MUST specify a range of lines to be centered using Cnn or CC"
    Address ISPEXEC "SETMSG MSG(ISRZ001)"                                       
    Exit (12)                                                                   
    End                                                                         
address ISREDIT "(FR)  = LINENUM .ZFRANGE"                                      
address ISREDIT "(LR)  = LINENUM .ZLRANGE"                                      
address ISREDIT "(LB,RB) = BOUNDS"                                              
If right ^=  "" Then Do                                                         
    rb = right                                                                  
    lb = left                                                                   
    End                                                                         
i = fr                                                                          
Do while (i <= lr)                                                              
  Address ISREDIT                                                               
  Address ISREDIT "LABEL" i ".LJ"                                               
  Address ISREDIT "SEEK P'-' .LJ .LJ" lb rb "FIRST"                             
  Address ISREDIT "(LLINE,LCOL) = CURSOR"                                       
  Address ISREDIT "SEEK P'-' .LJ .LJ" lb rb "LAST"                              
  Address ISREDIT "(RLINE,RCOL) = CURSOR"                                       
  midpt = (rb  - lb) % 2                                                        
  midpt = midpt + lb                                                            
  left = midpt - lcol                                                           
  right = rcol - midpt                                                          
  count = (left  - right + 1) % 2                                               
  If count > 0                                                                  
    Then                                                                        
      Address ISREDIT "SHIFT )" i count                                         
    Else                                                                        
      If count < 0 Then Do                                                      
          count = -1*count                                                      
          Address ISREDIT "SHIFT (" i count                                     
          End                                                                   
  If i = fr                                                                     
    Then                                                                        
      Address ISREDIT "LABEL" i ".LJX"                                          
  i = i + 1                                                                     
  End                                                                           
Address ISREDIT "SEEK P'=' .LJ .LJ FIRST"                                       
Exit (0)                                                                        
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/*                           End of CENTER                           */         
/*-------------------------------------------------------------------*/